Rain Crow (oz16537)

About this Plan

Rain Crow. Simple hand launch glider model. Wingspan 18 in.

Quote: "DO YOU HAVE an urge to get outside with some guys of like interest for some exhilarating activity related to flight? And that without having had first to invest a mint in cash, or spend many hours at the work table. Build this little jewel and happily satisfy that yearning. At the same time you'll be creating a quite competi-tive flyer too. This model won a few club contests.

Of my five or six gliders of different designs, Rain Crow is definitely superior. It displays a beautiful pull-out,or you might say recovery, from a viciously hard righthanded launch, followed by a stable left-circling glide. Its glide is, in fact, as stable or more so than any glider I've ever flown, particularly in windy weather.

As for the design, it can't be claimed that the Rain Crow's enhancing qualities were wholly arrived at by approaches which were very scientific. Mother Nature as-sisted quite a bit. How is this possible? This glider was lost about dusk. It rained that night, warping the wing and tail terribly. After an only partially successful attempt was made at removing the wing warps, simply replacing the tail, the glider again was flown. A remarkable pull-out immediately became evident but the glide was an ever tightening left circle culminating in a spiral dive.

Happily, deflecting the small vertical tail in a manner which would ordinarily induce a right turn was all that was re-quired to stabilize the left-glide circle without removing it. A tiny amount of weight added to the left wing tip may be found to improve the launch phase but is not a prerequisite for excellent flights.

Construction: Select medium-grade balsa for the wing and tail. Nothing special, just try to select wood that doesn't have mushy areas or irregular grain. The tail surfaces may be quickly sanded to 1/20 thickness from 1/16 sheet if you can't secure 1/20 stock. Actually, some so-called 1/16 stock is nearer to 1/20 thick. The wing requires the most hand work, but this can be reduced considerably if you have a small wood plane to shave the wing down to somewhere near its final contours. Since the wing has some twist the trailing edge will be raised slightly above the horizontal in some areas and should be inked on the edge of the wing-blank. Refer to the drawing for the correct amount. This will give you a reference line to shave for the wing's upper and lower surface. Note that there are different degrees of twist in each wing panel. The drawing also indicates a small amount of undercamber to be cut into each panel. Once you get the wing contour shaved to within 1/64 of the final contour, take about a 4-in square piece of medium sandpaper (grit about the size of table salt), wrap it around a sanding block, and sand all the shave marks out of the wing surfaces.

Then use fine grit sandpaper to sand the wing until no sandpaper scratches remain from the previous sanding. Finally, using extra fine paper, sand the wing contour till there are no scratches whatsoever. Employ the same sanding procedures in the case of the tail surfaces. When sanding down the wing and tail surfaces always use a sanding block. One, two or three inches wide and three or four long can easily be held in your hand with a sheet of sand-paper held tightly wrapped around it. The use of a sanding block cuts down high areas left by shaving..."

Direct submission to Outerzone.

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